if the school is blocking syndication.google.com there isn't a work around for this that I have found...
This is fairly common, most open wi-fi services will also block this if it's properly setup.
I'm not sure how I feel about that myself... I think there are more worth while things to block, but if your site depends on that traffic and the ad views your going to need to look for another source to earn a living.
On the Plus side those page views are not counted against you if the ads aren't shown.